To protect your lungs, never blow at accumulated pastel dust. Take the
work outside or hold it over a newspaper and tap the back to get rid of
Wearing a mask helps protect against inhalation of pastel dust and if you are using this medium daily, an air filter in your working space is a good idea.
Pastel pigment can be absorbed through the skin. Try to get used to wearing disposable gloves. Gloves also help keep the work clean and it is much easier to clean the pigment off the gloves before changing colours than off your hands.
As an alternative to gloves, and to prevent dry skin, breaking nails or sweaty hands from gloves try "Artguard Barrier" Cream by "Windsor & Newton". Just put it on before you touch a pastel stick.
When using fixatives, spray in a well-ventilated area, preferably in a garage or outside.